Circuit Description
The extended travel brake switch is a normally closed switch. With the brake pedal NOT applied, the PCM should detect a high signal voltage on the extended travel brake switch circuit. With the brakes applied, the PCM compares the extended travel brake switch input to the TCC and/or Stoplamp switch input. If a signal transition occurs on the TCC and/or Stoplamp switches without a transition on the extended travel brake switch, DTC P1575 will set.
Conditions for Running the DTC
| • | Engine Speed is greater than 500 RPM. |
| • | No VSS, TCC brake switch, Stoplamp brake switch, or EBCM Serial Data DTCs are set. |
| • | Traction control and antilock brake systems have not failed |
| • | Traction control and antilock brake systems are not active. |
| • | VSS achieves 32 km/h (20 mph) and remains above 5 km/h (3 mph). |
| • | The difference in speed between the driven wheels and the non-driven wheels is less than 10 km/h (6 mph). |
Conditions for Setting the DTC
The PCM detects a transition on the TCC and/or stoplamp switches without a transition on the extended travel brake switch
Action Taken When the DTC Sets
| • | The PCM will not illuminate the malfunction indicator lamp (MIL). |
| • | PCM disables cruise control. |
| • | The PCM will store conditions which were present when the DTC set as Failure Records only. |
Conditions for Clearing the DTC
| • | The PCM will request that the message be turned OFF after one diagnostic test has been run and passed. |
| • | The History DTC will be cleared after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
If the condition is intermittent, refer to Intermittent Conditions in Symptoms.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||||||||
2 |
Does the scan tool display indicate Released? | -- | ||||||||
3 | Depress the brake pedal approximately half-way. Does the scan tool display indicate Applied? | -- | Go to Diagnostic Aids | |||||||
4 | Disconnect the extended travel brake switch connector. Does the scan tool display indicate Applied? | -- | ||||||||
5 | Test for a short to voltage on the extended travel brake switch signal circuit. Did you find and correct the condition? | -- | ||||||||
6 | With a scan tool, observe the TCC brake switch display. Does the scan tool display indicate Released? | -- | ||||||||
7 |
Did you find and correct the condition? | -- | ||||||||
8 |
Does the scan tool indicate Released? | -- | ||||||||
9 | Inspect for poor connections at the TCC/extended travel brake switch. Did you find and correct the condition? | -- | ||||||||
10 | Test for the following conditions:
Did you find and correct the condition? | -- | ||||||||
11 | Inspect the Rly IGN 1 for an open fuse. Is the fuse open? | -- | ||||||||
12 |
Did you find and correct the condition? | -- | Go to Diagnostic Aids | |||||||
13 | Test for an open in the ignition feed circuit to the TCC/extended travel brake switch assembly. Did you find and correct the condition? | -- | ||||||||
14 | Test for proper TCC/extended travel brake switch adjustment. Did the switch require adjustment? | -- | ||||||||
15 | Replace the TCC/extended travel brake switch. Is the action complete? | -- | -- | |||||||
16 |
Important: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is action complete? | -- | -- | |||||||
17 |
Does the scan tool indicate that DTC P1575 passed? | -- | System OK |
